Determining outages of a satellite navigation system and signal interference

Abstract

A method of supporting flight operations of aircraft includes accessing a data stream of geographic positions of aircraft on respective flights. The geographic positions are determined using a satellite navigation system and obtained from automatic dependent surveillance broadcast (ADS-B) position reports, or estimated independent of the ADS-B position reports. The geographic positions are tracked to determine a number of the respective flights for which the geographic positions change from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports. The method includes determining an outage in which the satellite navigation system is unavailable to the aircraft, based on the number of the respective flights for which the geographic positions change from the ADS-B position reports to estimated independent of the ADS-B position reports, and based on a threshold. And an outage notification is generated that is output to alert users of the outage.

What is claimed is: 
     
       1. An apparatus for supporting flight operations of aircraft, the apparatus comprising:
 a memory configured to store computer-readable program code; and 
 processing circuitry configured to access the memory, and execute the computer-readable program code to cause the apparatus to at least: 
 access a data stream of geographic positions of aircraft on respective flights, the geographic positions obtained from automatic dependent surveillance broadcast (ADS-B) position reports, or estimated independent of the ADS-B position reports, those of the geographic positions obtained from the ADS-B position reports determined using a satellite navigation system; 
 track the geographic positions of the aircraft to determine a number of the respective flights for which the geographic positions change from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports; 
 determine an outage in which the satellite navigation system is unavailable to the aircraft, based on the number of the respective flights for which the geographic positions change from the ADS-B position reports to estimated independent of the ADS-B position reports, and based on a threshold; 
 generate an outage notification that is output to alert users of the outage; 
 wherein the respective flights of the aircraft are in an airspace that is divided into geographic areas; and 
 wherein the outage is determined for a geographic area of the geographic areas along the respective flights based on those of the geographic positions of the aircraft within the geographic area that change from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports. 
 
     
     
       2. The apparatus of  claim 1 , wherein the outage is determined for multiple of the geographic areas based on those of the geographic positions within respective ones of the multiple geographic areas that change from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports. 
     
     
       3. The apparatus of  claim 1 , wherein the threshold is expressed as a threshold percentage, and the outage is determined when the number of the respective flights, expressed as a percentage of a total number of the respective flights, exceeds the threshold percentage. 
     
     
       4. The apparatus of  claim 1 , wherein the data stream includes the geographic positions of the aircraft within a time interval, and the processing circuitry is configured to execute the computer-readable program code to cause the apparatus to further determine the threshold for the time interval. 
     
     
       5. The apparatus of  claim 4 , wherein the threshold is determined based on historical flights of aircraft for an earlier time interval during which the satellite navigation system was unavailable. 
     
     
       6. The apparatus of  claim 5 , wherein the apparatus caused to determine the threshold includes the apparatus caused to:
 access flight data for the historical flights that includes the geographic positions of the aircraft on the historical flights; 
 determine a number of the historical flights for which the geographic positions changed from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports; and 
 determine the threshold as the number of the historical flights, expressed as a percentage of a total number of the historical flights. 
 
     
     
       7. The apparatus of  claim 1 , wherein the data stream further includes corresponding geographic positions of the aircraft obtained from data sources distinct from the ADS-B position reports and the satellite navigation system, and the processing circuitry is configured to execute the computer-readable program code to cause the apparatus to further at least:
 determine signal interference in the satellite navigation system based on a comparison of those of the geographic positions determined using the satellite navigation system, and the corresponding geographic positions; and 
 generate an interference notification that is output to alert users of the signal interference in the satellite navigation system. 
 
     
     
       8. The apparatus of  claim 7 , wherein the signal interference is determined when the geographic positions differ from the corresponding geographic positions by more than a difference threshold. 
     
     
       9. The apparatus of  claim 1  wherein respective geographic areas are visually marked to indicate different numbers of geographic positions within those ones of the geographic areas that change from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports. 
     
     
       10. A method of supporting flight operations of aircraft, the method comprising:
 accessing a data stream of geographic positions of aircraft on respective flights, the geographic positions obtained from automatic dependent surveillance broadcast (ADS-B) position reports, or estimated independent of the ADS-B position reports, those of the geographic positions obtained from the ADS-B position reports determined using a satellite navigation system; 
 tracking the geographic positions of the aircraft to determine a number of the respective flights for which the geographic positions change from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports; 
 determining an outage in which the satellite navigation system is unavailable to the aircraft, based on the number of the respective flights for which the geographic positions change from the ADS-B position reports to estimated independent of the ADS-B position reports, and based on a threshold; 
 generating an outage notification that is output to alert users of the outage; 
 wherein the respective flights of the aircraft are in an airspace that is divided into geographic areas; and 
 wherein the outage is determined for a geographic area of the geographic areas of the respective flights based on those of the geographic positions of the aircraft within the geographic area that change from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports. 
 
     
     
       11. The method of  claim 10 , wherein the outage is determined for multiple of the geographic areas based on those of the geographic positions within respective ones of the multiple geographic areas that change from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports. 
     
     
       12. The method of  claim 10 , wherein the threshold is expressed as a threshold percentage, and the outage is determined when the number of the respective flights, expressed as a percentage of a total number of the respective flights, exceeds the threshold percentage. 
     
     
       13. The method of  claim 10 , wherein the data stream includes the geographic positions of the aircraft within a time interval, and the method further comprises determining the threshold for the time interval. 
     
     
       14. The method of  claim 13 , wherein the threshold is determined based on historical flights of aircraft for an earlier time interval during which the satellite navigation system was unavailable. 
     
     
       15. The method of  claim 14 , wherein determining the threshold includes:
 accessing flight data for the historical flights that includes the geographic positions of the aircraft on the historical flights; 
 determining a number of the historical flights for which the geographic positions changed from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports; and 
 determining the threshold as the number of the historical flights, expressed as a percentage of a total number of the historical flights. 
 
     
     
       16. The method of  claim 10 , wherein the data stream further includes corresponding geographic positions of the aircraft obtained from data sources distinct from the ADS-B position reports and the satellite navigation system, and the method further comprises:
 determining signal interference in the satellite navigation system based on a comparison of those of the geographic positions determined using the satellite navigation system, and the corresponding geographic positions; and 
 generating an interference notification that is output to alert users of the signal interference in the satellite navigation system. 
 
     
     
       17. The method of  claim 16 , wherein the signal interference is determined when the geographic positions differ from the corresponding geographic positions by more than a difference threshold. 
     
     
       18. A computer-readable storage medium for supporting flight operations of aircraft, the computer-readable storage medium being non-transitory and having computer-readable program code stored therein that, in response to execution by processing circuitry, causes an apparatus to at least:
 access a data stream of geographic positions of aircraft on respective flights, the geographic positions obtained from automatic dependent surveillance broadcast (ADS-B) position reports, or estimated independent of the ADS-B position reports, those of the geographic positions obtained from the ADS-B position reports determined using a satellite navigation system, wherein the respective flights of the aircraft are in an airspace that is divided into geographic areas; 
 track the geographic positions of the aircraft to determine a number of the respective flights for which the geographic positions change from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports; 
 determine an outage in which the satellite navigation system is unavailable to the aircraft, based on the number of the respective flights for which the geographic positions change from the ADS-B position reports to estimated independent of the ADS-B position reports, and based on a threshold; 
 generate an outage notification that is output to alert users of the outage; and 
 wherein the outage is determined for a geographic area of the geographic areas along the respective flights based on those of the geographic positions of the aircraft within the geographic area that change from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports. 
 
     
     
       19. The computer-readable storage medium of  claim 18 , wherein the data stream further includes corresponding geographic positions of the aircraft obtained from data sources distinct from the ADS-B position reports and the satellite navigation system, and the computer-readable storage medium has further computer-readable program code stored therein that, in response to execution by the processing circuitry, causes the apparatus to further at least:
 determine signal interference in the satellite navigation system based on a comparison of those of the geographic positions determined using the satellite navigation system, and the corresponding geographic positions; and 
 generate an interference notification that is output to alert users of the signal interference in the satellite navigation system. 
 
     
     
       20. An apparatus for supporting flight operations of aircraft, the apparatus comprising:
 a memory configured to store computer-readable program code; and 
 processing circuitry configured to access the memory, and execute the computer-readable program code to cause the apparatus to at least: 
 access a data stream of geographic positions of aircraft on respective flights, the geographic positions obtained from automatic dependent surveillance broadcast (ADS-B) position reports, or estimated independent of the ADS-B position reports, those of the geographic positions obtained from the ADS-B position reports determined using a satellite navigation system; 
 track the geographic positions of the aircraft to determine a number of the respective flights for which the geographic positions change from being obtained from the ADS-B position reports, to being estimated independent of the ADS-B position reports; 
 determine an outage in which the satellite navigation system is unavailable to the aircraft, based on the number of the respective flights for which the geographic positions change from the ADS-B position reports to estimated independent of the ADS-B position reports, and based on a threshold; 
 generate an outage notification that is output to alert users of the outage; and 
 wherein the threshold is expressed as a threshold percentage, and the outage is determined when the number of the respective flights, expressed as a percentage of a total number of the respective flights, exceeds the threshold percentage.